Why aren't there more feelgood gay films? Gay cinema can do drama, comedy, romance, sex and tragedy rather well. But it's not so hot on happy-ever-after endings. The gay character usually winds up dead, or mad. Or mad, then dead. Two films at London's Gay and Lesbian film festival confirmed my fears: both were coming-out stories in which the protagonists die by the age of about 20. One by his own hand; the other is hit by a car as she stands, torn between running after the woman she's fallen in love with, or turning back to the boyfriend she's planning to leave. Not enormously uplifting endings - particularly for any young gay people in the audience who might be struggling to come out themselves.

These two films, Prayers for Bobby and Eloïse, are very different. Prayers for Bobby is an important film, made for US TV last year, in which Sigourney Weaver plays a self-righteous, highly religious housewife who prides herself on her close-knit, loving family, but rejects her once-beloved son Bobby when he admits his feelings for men. He's forced from the family home after mum's attempts to have him "cured" fail. Then, when his first tentative romance with a man also ends in rejection, he throws himself off a bridge into the path of a lorry.

It's only after sacrificial Bobby's suicide does his mother begin to question her beliefs. With the help of a gay-friendly minister and a support group for parents of gay children, she comes to realise, with great anguish, that her behaviour contributed to her son's death, and profoundly regrets not accepting his homosexuality. She ends up an advocate for gay rights, travelling to San Francisco to attend a Pride march and speaking at a council meeting to get a "gay day" in her own town. It's a total tearjerker, with a powerhouse performance from Weaver. When a photograph of the mother and son on whose story the film is based flashes up on screen at the end, it ensures you're left with an awful added sadness that lingers long after the credits. This film isn't just telling one person's story, it represents countless other similar lives, cut short by fear and bigotry.

Eloïse, on the other hand, abounds in standard-issue, soft-core cliches. The storyline is classically predictable: Àsia, a beautiful young architecture student finds herself inexplicably drawn to an ad for a life model posted by art student and "openly gay, mysterious and exotic" Eloïse, played by a young Angelina Jolie lookalike (a no-brainer casting decision there). They bond during several sessions in which Eloïse sketches the fully clothed Àsia. Soon, though, Eloïse says that she's happy with the sketches, "but we could go further" and suggests Àsia models for her nude (the canny audience collectively sniggered on that "but …"). In cinema, there are few nude life models who don't, at some point, retire to the bedroom, and Eloïse doesn't fail us on that front. Àsia gradually falls in love with Eloïse, decides to leave her boyfriend to embark on a beautiful new future with her, then … bam! She's dead. Well, nearly. She spends some time in a coma first. And the idea of riding off into the sunset is only ever a dream (nicely illustrated by the two girls cuddling on a bus that drives into a hazy, Technicolor-orange horizon).

So: Eloïse is just a typical below-par lesbian drama, whereas Prayers for Bobby - along with those films dealing with the effect of Aids on the gay community, for example - is a valuable means of recording and expressing recent gay experience. Yet both screenings left me feeling quite flat as a gay person, and wondering why unhappy gay endings seem more frequent than happy ones? Sure, part of our history is unhappy, and it's right to reflect that – Hollywood's long-standing habit of sidelining and killing off gay characters is also accountable – but that doesn't explain it all.

Is it that we never really adjust to the heterosexual world after coming out? Always aware that, having departed from the mainstream script ourselves, we're making it up as we go along, so there are no assumptions about the future? Is happy-ever-after too boring? Too normal? Do we resist such narratives because it would mean leaving behind those who didn't make it? Or is it because we know that for many gay people in the world, there is still no happy-now, let alone ever-after?